While a minimum clearance between the gears in RA and DEC axis can be tolerable in a visual use of the telescope, it may become a real problem in astrophotography especially in windy conditions.
In my case the gear play was featured prominently on the RA axis. It was a play of about 15-17 arc-minutes (half the diameter of the Moon) when idecided to intervene.
In the following pages i describe my attempt on the RA in order to eliminate such play.
This procedure can be followed in a similar way for the DEC axis.
I will describe only how i eliminated the gear play and therefore i will not be touching topics such as, degreasing, cleaning and refurbishing of the mount.The task of eliminating the gear play requires minor inasivity and does not require any type of cleaning or replacement of the grease.
So lets start with the tools i used:
1) Allen key supplied with the mount
2) cross-head screwdrivers of various diameters.
3) (in my case) a complete set of Allen keys.(I used only the smallest for adjustment of the worm gear mesh.
First, i removed the OTA and the cables of HC and DEC motor and separated the DEC axis from RA for more comfort during work.
To separate the DEC axis from RA I removed the plastic cover of the polar scope behind, and then I unscrewed the part where you put the polar scope,the one with the graduated circles. Once this done then I unscrewed the 2 Allen screws on the front of the mount.At this point the DEC axis can be separated safely and put on the table while the i lehft the RA on the mount so i can work on it.
(click on the pictures to view in larger size)
Then I had to remove even the other part, together with the motor and the boards.Nothing easier than that, just unscrew the Allen screw from the rear end of the mount axis with attention 'cause once unscrewed isfree from detaching. Here's the screw:
(click on the pictures for viewing a larger version)
Here is the position:
So by tightening the adjustment screw (clockwise motion), increases the distance between worm-gear and the “Crown “.
and loosens the grip so the gear play increases ... and the oposite.
The important thing is finding the right compromise between hardness and lack of gear play
It's not difficult at all it just needs patience. I managed to eliminate all of the gear play and the axis is softer than before
Here's the photo where I act on the adjustment screw:
Then:) I put the motor block back and locked it into place with the only screw Allen that keeps it there from behind.
B) I closed the plastic shell of RA, put screws back by and paying attention to cables and adapters.
I include a picture where you see the position of the electronic boards inside the shell.The positions are symmetric with the other shell and there are proper channels where you insert boards.
According my opinion replacing the grease definitely affects morbidity but not as significantly as this procedure ,and must be done so, only when absolutely necessary.
From what I managed to see the factory grease was enough and of decent quality.
For the DEC axis, the steps to follow are virtually identical in cases that we need to intervene.
I post the photos of the dec axis parts for your convenience: (click to enlarge)
I ask sorry for any grammatical and expression mistakes.